Substrate transfer unit, and substrate processing apparatus

ABSTRACT

A transfer machine that charges a substrate contained in a substrate container to a substrate holder; a drive member that operates the transfer machine; and an operation controller that monitors whether a torque value detected from the drive member is kept within a torque limit value of the transfer machine by comparing the torque value with the torque limit value which is set individually for each of an interference area and a non-interference area excluding the interference area relative to conveyance operation in which the transfer machine is moved toward at least one of the substrate container and the substrate holder. The torque limit value in the non-interference area is set larger than the torque limit value in the interference area where a part of the transfer machine interferes with at least one of the substrate container and the substrate holder.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This non-provisional U.S. patent application is a Bypass Continuation Application of International Application No. PCT/JP2018/006956, filed on Feb. 26, 2018, in the WIPO, which claims priority to Japanese Patent Application No. 2017-064678, filed on Mar. 29, 2017, in the Japanese Patent Office. The entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This present disclosure relates to a substrate transfer unit, and a substrate processing apparatus.

RELATED ART

The substrate processing apparatus includes an operation controller that controls a conveyance mechanism that conveys a substrate in order to perform substrate processing. Additionally, the operation controller provides an operation command to an actuator in order to perform operation control, and the actuator executes the operation command within a limit value of rated torque and within a scope of the operation command.

In the substrate processing apparatus, in a case where torque exceeding a torque limit value acts on the actuator, such as contacting with another member during operation of the conveyance mechanism, the conveyance mechanism is stopped to prevent damage to the conveyance mechanism and the like.

In a conventional substrate processing apparatus, only one kind of a torque limit value can be set. Therefore, it is necessary to set the torque limit value to a maximum torque value or larger generated in a non-interference area (an acceleration area at the time of starting conveyance) where there is no possibility of contacting with another member. The torque limit value is larger than a torque value normally generated in an interference area (a constant velocity area during the conveyance and a deceleration area after completion of the conveyance) where there is a possibility of contacting with another member. Due to this, even in a case where the conveyance mechanism collides with another member in the interference area, the collision cannot be detected immediately, and there is a possibility that a component may be damaged.

SUMMARY

This present disclosure provides a technology in which damage to a substrate and a substrate holder can be suppressed by urgently stopping a transfer machine even in the event of an abnormality during substrate conveyance.

According to an embodiment of this present disclosure, provided is a technology including: a transfer machine that charges a substrate contained in a substrate container to a substrate holder; a drive member that operates the transfer machine; and an operation controller configured to monitor whether a torque value detected from the drive member is kept within a torque limit value by comparing the torque value with the torque limit value of the transfer machine, the torque limit value being individually set for each of an interference area and a non-interference area excluding the interference area relative to conveyance operation in which the transfer machine is moved toward at least one of the substrate container and the substrate holder, the torque limit value in the non-interference area being set larger than the torque limit value in the interference area where a part of the transfer machine interferes with at least one of the substrate container and the substrate holder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a substrate processing apparatus according to a practical example of this present disclosure.

FIG. 2 is a side sectional view illustrating the substrate processing apparatus according to the practical example of this present disclosure.

FIG. 3 is a block diagram illustrating a control system in the substrate processing apparatus.

FIG. 4 is a top view illustrating conveyance of a substrate between a substrate container and a substrate holder.

FIG. 5 illustrates torque values detected during substrate conveyance processing, a left diagram is a graph illustrating a torque value in a case where no collision occurs, and a right diagram is a graph illustrating a torque value in a case where collision occurs.

FIG. 6 is an explanatory view illustrating a state in which the transfer machine collides with the substrate holder.

FIG. 7 is an operation stop flow performed by the operation controller in FIG. 6.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a practical example of this present disclosure will be described with reference to the drawings. FIGS. 1 and 2 illustrate a vertical substrate processing apparatus as an example of a substrate processing apparatus. Note that a wafer made from silicon or the like is illustrated as an example of a substrate to be processed in the substrate processing apparatus.

The substrate processing apparatus 1 includes a housing 2, a front maintenance port 4 as an opening provided at a lower portion of a front wall 3 of the housing 2 in a manner such that maintenance can be performed from the opening, and the front maintenance port 4 is opened/closed by a front maintenance door 5.

A pod loading/unloading port 6 is opened on the front wall 3 of the housing 2 so as to provide communication between the inside and outside of the housing 2, the pod loading/unloading port 6 is opened/closed by a front shutter 7, a load port 8 is installed on a front side of the pod loading/unloading port 6, and the load port 8 adjusts a position of a mounted pod 9.

The pod 9 is a closed type substrate container, which is loaded onto the load port 8 and unloaded from the load port 8 by a conveyance device in a processing step not illustrated.

A rotary pod shelf 11 rotatable in a CR axis direction is installed at an upper portion of a substantially center portion in a front-rear direction inside the housing 2, and the rotary pod shelf 11 stores a plurality of pods 9.

The rotary pod shelf 11 includes a column 12 that is erected vertically and intermittently rotated, and a plurality of shelf boards 13 radially supported at respective positions of upper, middle, and lower stages in the column 12. The shelf boards 13 store the plurality of pods 9 in a state that the pods 9 are mounted thereon.

A pod opener 14 is provided below the rotary pod shelf 11, a pod 9 is mounted on the pod opener 14, and the pod opener 14 can open/close a lid of the pod 9.

A pod conveyance device 15 is installed between the load port 8, the rotary pod shelf 11, and the pod opener 14. Additionally, the pod conveyance device 15 holds the pod 9 and is movable up and down in a CZ-axis direction, movable back and forth in a CX-axis direction, and movable laterally in a CS-axis direction, and conveys the pod 9 between the load port 8, the rotary pod shelf 11, and the pod opener 14.

At a lower portion of the substantially center portion in the front-rear direction of the housing 2, a sub-housing 16 is provided extending to a rear end. A pair of wafer loading/unloading ports 19 used to load/unload wafers (substrates) 18 into/from the sub-housing 16 is vertically arrayed and opened in parallel in upper and lower two stages on a front wall 17 of the sub-housing 16, and the pod opener 14 is provided in each of the upper and lower stages of the wafer loading/unloading ports 19.

The pod opener 14 includes a mounting table 21 to mount the pod 9, and an open/close mechanism 22 that open/closes the lid of the pod 9. The pod opener 14 opens/closes, by the open/close mechanism 22, the lid of the pod 9 mounted on the mounting table 21, thereby opening/closing a wafer entrance of the pod 9.

The sub-housing 16 constitutes a transfer chamber 23 that is hermetically sealed from a space (pod conveyance space) in which the pod conveyance device 15 and the rotary pod shelf 11 are disposed. A wafer conveyance mechanism (hereinafter, also referred to as a transfer machine) 24 is installed in a front area of the transfer chamber 23, and the transfer machine 24 includes required number (five in the drawings) of wafer mounting plates (substrate supports) 25 to mount the wafers 18, and each wafer mounting plate 25 is linearly movable in a horizontal direction (X-axis), rotatable in a horizontal direction (Y-axis), and movable in an up-down direction (Z-axis). The transfer machine 24 charges/discharges the wafers 18 onto/from the boat (substrate holder) 26.

The following four parameters are set for the transfer machine 24: the X-axis that is an axis to adjust operation in an entering direction of each wafer mounting plate 25 when the wafer mounting plate 25 that is holding a wafer 18 picks up the wafer 18 from a predetermined place and mounts the wafer 18 in a predetermined place, the Y-axis that is an axis to adjust an entering angle of the wafer mounting plate 25 at the time of transferring the wafer 18 to the boat 26, the Z-axis that is an axis to adjust an entering height of the wafer mounting plate 25 at the time of transferring the wafer 18 to the boat 26, and a V-axis to adjust an insertion interval of the wafer 18 to the boat 26 by performing fine adjustment of the Z-axis.

In a rear area of the transfer chamber 23, a standby space 27 to house the boat 26 and keep the boat 26 standby is formed, and a vertical process furnace 28 is provided above the standby space 27. The process furnace 28 forms a process chamber 29 inside thereof, a lower end of the process chamber 29 constitutes a furnace throat, and the furnace throat is opened/closed by a furnace throat shutter 31.

A boat elevator 32 used to move the boat 26 up and down is installed between a right end of the housing 2 and a left end of the standby space 27 of the sub-housing 16. A seal cap 34 as a lid is horizontally attached to an arm 33 connected to an elevation table of the boat elevator 32, the lid 34 perpendicularly supports the boat 26, and can hermetically close the furnace throat in a state that the boat 26 is inserted into the process chamber 29.

The boat 26 aligns centers of a plurality of (for example, about fifty to one hundred seventy-five) wafers 18 and holds the wafers in multiple stages in a horizontal posture.

A clean unit 35 is disposed at a position facing the boat elevator 32 side, and the clean unit 35 includes a supply fan to supply clean air 36 that is a purified atmosphere or an inert gas, and a dustproof filter. A notch alignment device (not illustrated) as a substrate alignment device that aligns circumferential positions of the wafers 18 is installed between the transfer machine 24 and the clean unit 35.

The clean air 36 blown out from the clean unit 35 is made to flow through the notch alignment device (not illustrated), the transfer machine 24, and the boat 26, and then sucked to a duct (not illustrated), and after that, the clean air is exhausted to the outside of the housing 2 or blown to the inside of the transfer chamber 23 again by the clean unit 35.

Next, operation of the substrate processing apparatus 1 will be described.

When each pod 9 is supplied to the load port 8, the pod loading/unloading port 6 is opened by the front shutter 7. The pod 9 on the load port 8 is loaded into the housing through the pod loading/unloading port 6 by the pod conveyance device 15, and mounted on a designated shelf board 13 of the rotary pod shelf 11. The pod 9 is temporarily kept in the rotary pod shelf 11, and then is conveyed from the shelf board 13 to one of the pod openers 14 by the pod conveyance device 15 and transferred onto the mounting table 21 or directly transferred to the mounting table 21 from the load port 8.

At this time, the wafer loading/unloading port 19 is closed by the open/close mechanism 22, and the clean air 36 is made to flow into the transfer chamber 23.

An opened-side end surface of the pod 9 mounted on the mounting table 21 is pressed against an opening edge of the wafer loading/unloading port 19 on the front wall 17 of the sub-housing 16 and the lid is removed by the open/close mechanism 22 to open the wafer entrance.

When the pod 9 is opened by the pod opener 14, wafers 18 are picked out from the pod 9 by the transfer machine 24 and conveyed to the notch alignment device (not illustrated). After aligning the positions of the wafers 18 with the notch alignment device, the transfer machine 24 loads the wafers 18 to the standby space 27 located behind the transfer chamber 23 and charges the wafers to boat 26 (charging).

The transfer machine 24 having transferred the wafers 18 to the boat 26 returns to a pod 9 and charges the next set of wafers 18 to the boat 26.

During the charging operation of the wafers 18 to the boat 26 by the transfer machine 24 in one of the pod openers 14 (in the upper or lower stage), a different pod 9 is conveyed by the pod conveyance device 15 to the other pod opener 14 (in the lower or upper stage) from the rotary pod shelf 11, and opening operation of the pod 9 by the other pod opener 14 is simultaneously performed.

When the predetermined number of wafers 18 are charged to the boat 26, the furnace throat of the process furnace 28 that has been closed by the furnace throat shutter 31 is opened by the furnace throat shutter 31. Subsequently, the boat 26 is moved up by the boat elevator 32 and loaded into the process chamber 29 (loading).

After the loading, the furnace throat is hermetically closed by the lid 34.

The process chamber 29 is subjected to vacuum exhaust by a gas exhaust mechanism (not illustrated) so as to obtain a desired pressure (vacuum degree). Additionally, the process chamber 29 is heated to a predetermined temperature by a heater (not illustrated) so as to have a desired temperature distribution.

A processing gas controlled to have a predetermined flow rate is supplied by a gas supply mechanism (not illustrated), and the processing gas contacts a surface of each wafer 18 in a process of making the processing gas flow in the process chamber 29, and a thin film is deposited on the surface of the wafer 18 by thermal CVD reaction at the time of the contact. Furthermore, the processing gas after the reaction is exhausted from the process chamber 29 by the gas exhaust mechanism.

When a preset processing time has elapsed, an inert gas is supplied from an inert gas supply source (not illustrated) by the gas supply mechanism, and the atmosphere inside the process chamber 29 is replaced with the inert gas and also the pressure of the process chamber 29 is returned to a normal pressure.

The boat 26 is moved down by the boat elevator 32 via the lid 34.

As for unloading of the wafer 18 after the processing, the wafers 18 and the pod 9 are discharged from the housing 2 in a procedure reverse to the procedure described above. Unprocessed wafers 18 are further charged to the boat 26, and batch processing of the wafers 18 is repeated.

Now, a description will be provided with reference to FIG. 3 regarding: the conveyance mechanism that conveys a pod 9 housing a plurality of wafers 18 between the load port 8, the rotary pod shelf 11, and each pod opener 14; the conveyance mechanism that conveys the wafers 18 inside the pod 9 to the boat 26 and conveys the boat 26 to the process furnace 28; the gas supply mechanism that supplies a processing gas and the like to the process furnace 28; the gas exhaust mechanism that exhausts the gas contained inside the process furnace 28; the heater that heats the process furnace 28 to the predetermined temperature; and a control device 37 that controls each of the conveyance mechanisms, the gas supply mechanism, the gas exhaust mechanism, and the heater. Note that the gas supply mechanism, the gas exhaust mechanism, the process furnace 28, and the heater constitute a substrate processing mechanism.

In FIG. 3, a reference sign 38 represents a process controller as a process system controller, a reference sign represents a conveyance controller as a conveyance system controller, and a reference sign 41 represents a main controller. The process controller 38 includes a storage 42, and the storage 42 stores a process execution program necessary to execute a process. The conveyance controller 39 includes a storage 43, and the storage 43 stores a conveyance program to execute the conveyance processing of the wafers 18, an operation control program to control operation of the three conveyance mechanisms including the pod conveyance device 15, the transfer machine 24, and the boat elevator 32, and a first torque limit value and a second torque limit value to control operation of the transfer machine 24. The main controller includes data storing means 44, and the data storing means 44 includes an external storage device such as an HDD. Note that the process execution program, the conveyance program, and the operation control program may also be stored in the data storing means 44.

Furthermore, sub-controllers 45, 46, and 47 are exemplified in FIG. 3. For example, the reference sign 45 represents a first sub-controller that performs heating control for the process furnace 28, the reference sign 46 represents a second sub-controller that controls a supply flow rate of the processing gas to the process furnace 28 by controlling opening/closing of a valve, operation of the flow rate controller and the like, and the reference sign represents a third sub-controller that controls gas exhaust from the process furnace 28 or controls the pressure of the process furnace 28. Similarly, FIG. 3 exemplifies actuators 48, 49, and 51. For example, the reference sign 48 represents a heater (hereinafter referred to as first process actuator) controlled by the first sub-controller 45, the reference sign 49 represents a flow rate controller (hereinafter referred to as second process actuator) controlled by the second sub-controller 46, and the reference sign 51 represents a pressure control valve (hereinafter referred to as a third process actuator) controlled by the third sub-controller 47. Note that only one in each of the process actuators is illustrated, but it is also fine that a plurality of process actuators in each of the process actuators is provided.

Reference signs 52, 53, and 54 represent sensors that detect states of the respective process actuators and feed back detection results to the first sub-controller 45, the second sub-controller 46, and the third sub-controller 47. For example, the reference sign 52 represents a temperature detector (hereinafter as “first process sensor”), the reference sign 53 represents a flow rate detector (hereinafter as a second process sensor), and the reference sign 54 represents a pressure sensor (hereinafter as a third process sensor). Note that one detector or one sensor is provided to detect the state of each of the process actuators, but it is also fine that a plurality of detectors or a plurality of sensors is provided.

The conveyance controller 39 controls various kinds of conveyance control modules, and the various kinds of conveyance control modules include a first operation controller 55, a second operation controller 56, and a third operation controller 57 that respectively control operation actuators described later.

A first-1 operation controller 55-1 as a driver controls a servomotor (hereinafter as a first operation actuator) 58 that is a drive member to drive the pod conveyance device 15 in the CX-axis direction, a first-2 operation controller 55-2 controls a servomotor (hereinafter as the first operation actuator) 59 that is a drive member to drive the pod conveyance device 15 in the CZ-axis direction, and a first-3 operation controller 55-3 controls a servomotor (hereinafter as the first operation actuator) 60 that is a drive member to drive the pod conveyance device 15 in the CS-axis direction. Additionally, a second-1 operation controller 56-1 as a driver controls a servomotor (hereinafter as a second operation actuator) 61 that is a drive member to drive the transfer machine 24 in the X-axis direction, a second-2 operation controller 56-2 controls a servomotor (hereinafter as the second operation actuator) 62 that is a drive member to drive the transfer machine 24 in the Y-axis direction, and a second-3 operation controller 56-3 controls a servomotor (hereinafter as the second operation actuator) 63 that is a drive member to drive the transfer machine 24 in the Z-axis direction, and a third operation controller 57 controls a servomotor (hereinafter as a third operation actuator) 64 that is a drive member to drive the boat elevator 32. Hereinafter, each servomotor may be simply referred to as a motor.

The respective operation actuator are provided with state detection sensors 65, 66, 67, 68, 69, 70, and 71 that detect, for the respective axes, states of the respective operation actuators (for example, positional states such as whether each of the actuators is at a limit point). The respective state detection sensor 65, 66, 67, 68, 69, 70, and 71 have functions to detect the states of the respective operation actuators and feed back detection results to the first operation controller 55, the second operation controller 56, and the third operation controller 57, respectively. Each of the operation controllers 55, 56, and 57 includes a memory and can temporarily store the feedback data (detection results). Note that, in the drawing, the state detection sensors 65, 66, 67, 68, 69, 70, and 71 are provided in the operation actuators 58, 59, 60, 61, 62, 63, and 64 respectively in a one-one relation, but not limited to this form. Needless to mention, a plurality of state detection sensors may be provided in each of the operation actuators.

As illustrated in FIG. 3, a torque sensor 81 is illustrated in the second-1 operation controller 56-1 intended for the X-axis of the transfer machine 24. This illustrates that parameters associated with the torque, such as the first torque limit value and the second torque limit value, are set in settings for adjusting operation in the entering direction of the wafer mounting plate 25 of the transfer machine 24. Note that a torque sensor is provided in each of the operation controllers 55, 56, and 57 to enable a setting for necessity of torque detection in each thereof. Additionally, a torque sensor is provided in each of the second operation controllers 56-1, 56-2, and 56-3 of the respective axes to enable the setting for necessity of torque detection in each thereof. Furthermore, for example, as for the (X-axis) operation of the second-1 operation controller 56-1, the parameters such as the first torque limit value and the second torque limit value are set relative to advancing operation in order to detect torque, and a setting so as not to detect torque is set (no torque limit value is set) relative to retracting operation. Note that the substrate transfer unit in the present embodiment includes at least the transfer machine 24, the driver 56-1, the motor 61, and the torque sensor 81 provided inside the driver 56-1, and the state detection sensor 68 may be included in the substrate transfer unit.

The first operation controller 55 performs drive control for the pod conveyance device 15 that transfers each pod 9 to each mounting table 21 from the load port 8. The second operation controller 56 performs drive control for the transfer machine 24 that picks out wafers 18 from the pod 9 and charges the wafers to the boat 26. The third operation controller 57 performs drive control for the boat elevator 32 that loads, into the process furnace 28, the boat 26 charged with the wafers 18.

An input device 72 represents a keyboard, a mouse, an operation panel, and the like, and a monitor 73 is an operational screen including a setting screen and the like. An operational unit 74 receives various kinds of commands from the monitor 73 by using the input device 72. For example, on the monitor 73, individual settings can be performed for the conveyance operation in which the transfer machine 24 is moved toward at least one of a pod 9 and the boat 26, and the conveyance operation in which the transfer machine 24 is moved away from at least one of the pod 9 and the boat 26.

A command for a set value or a command signal in accordance with a processing sequence is received from the process controller 38 in the first sub-controller 45, the second sub-controller 46, and the third sub-controller 47. The process controller 38 integrally controls the first sub-controller 45, the second sub-controller 46, and the third sub-controller 47 based on detection results detected by the first process sensor 52, the second process sensor 53, and the third process sensor 54.

The process controller 38 executes the substrate processing in accordance with a command from the operational unit 74 via the main controller 41. The substrate processing is executed by the process controller 38 independently from other control systems in accordance with the program stored in the storage 42. Therefore, even when a problem occurs in the conveyance controller 39 and the main controller 41, the substrate processing is completed without interruption.

Whether to perform torque control is preset in each of the operation actuators 58, 59, 60, 61, 62, 63, and 64. In the present embodiment, only the second operation actuator 61 is set to perform the torque control. In the second-1 operation controller 56-1, a setting for at least one of parameters including a target position, a speed, acceleration, deceleration, the first torque limit value, and the second torque limit value, and the like is input from the operational unit 74 via the conveyance controller 39, in addition to the setting for whether to execute the torque control. On the other hand, a command signal in accordance with the processing sequence is received in the main controller 41 from the conveyance controller 39.

The first-1 operation controller 55-1 controls the first operation actuator 58 based on a detection result detected by the state detection sensor 65. Also, the similar is applied to the first-2 operation controller 55-2 and the first-3 operation controller 55-3. The second-1 operation controller 56-1 controls the second operation actuator 61 based on a detection result detected by the state detection sensor 68. Also, the similar is applied to the second-2 operation controller 56-2 and the second-3 operation controller 56-3. The respective operation controllers control the respective operation actuators corresponding to the respective state detection sensors, and for example, the third operation controller 57 controls the third operation actuator 64 based on a detection result detected by the state detection sensor 71. Here, the torque sensor 81 illustrated inside the second-1 operation controller 56-1 limits, for example, torque generated by driving the motor 61 during drive of the motor 61 as the second operation actuator.

The conveyance controller 39 executes conveyance processing in accordance with a command from the operational unit 74. The pod 9 and the wafers 18 are conveyed by the conveyance controller 39 independently from the other control systems in accordance with the convey program and the operation control program stored in the storage 43. Therefore, even when a problem occurs in the process controller 38 and the main controller 41, the conveyance of the wafers 18 is accomplished without interruption.

The data storing means 44 stores, as files, various kinds of programs including a program to control progress of the substrate processing, a setting program to set processing content and processing conditions, recipes that store, for the substrate processing, setting information associated with heating of the process furnace 28, supply and exhaust of the processing gas, and the like, a communication program, an alarm information display program, and a parameter editing program, and the like.

The communication program is used to exchange data with the process controller 38 and the conveyance controller 39 via a communication means such as a LAN. Additionally, the alarm information display program is used to display, on the monitor 73, alarm information of an abnormality cause such as a cause of operation stop relative to the operation actuators 58, 59, 60, 61, 62, 63, and 64 in a case where an abnormality is detected by the state detection sensors 65, 66, 67, 68, 69, 70, 71 and the torque sensor 81. The parameter editing program is used to edit parameters necessary to set, for example, stop conditions and the like of the conveyance mechanism adopting the torque limit values or the like.

The data storing means 44 includes a data storing area. The data storing area stores the parameters necessary to convey wafers 18, and further stores setting information preset in the conveyance mechanism, detection results detected by the state detection sensors 65, 66, 67, 68, 69, 70, 71, and the torque sensor 81, and information such as a processing state.

When the conveyance processing of the wafers 18 is executed, setting values are input from the operational unit 74, and the setting values includes not only the preset information relative to whether to execute the torque control (in the present embodiment, torque is set for only the second operation controller), but also a target position, a speed, acceleration, deceleration in an interference area and a non-interference area described later, and a direction of the torque control, a first torque limit value in the interference area and a second torque limit value in the non-interference area in a case of executing the torque control, and the like. After that, when an execution command for the conveyance processing is input from the operational unit 74, the operation control program is executed in accordance with the conveyance program stored in the storage 43 and a command from the conveyance program. Note that the respective setting items to execute the conveyance processing of the wafers 18 may be transmitted to the operational unit 74 from a host computer in a factory.

When the convey program is executed, the conveyance controller 39 performs drive control for the respective conveyance mechanisms including the pod conveyance device 15, the wafer conveyance mechanism 24, and the boat elevator 32 via the first operation controller 55, the second operation controller 56, the third operation controller 57.

In the following, details of conveyance control between the pod 9 and the boat 26 by the transfer machine 24 will be described with reference to FIGS. 4 and 5.

FIG. 4 is a schematic view illustrating a relation between a pod 9, the transfer machine 24, and the boat 26. As illustrated in FIG. 4, the transfer machine 24 conveys wafers 18 by a predetermined convey distance in the X-axis direction, and transfers the wafer 18 to the pod 9 or the boat 26.

The transfer machine 24 inserts the wafer mounting plates 25 between the wafers 18 stacked at a narrow pitch on the pod 9 or the boat 26 in a manner such that a gap of about several millimeters is formed on an upper side and a lower side of each of the wafers 18.

When the wafers 18 are transferred, the transfer machine 24 mounts the wafers 18 on the wafer mounting plates 25 and is moved at a constant speed after acceleration to a maximum speed, and transfers the wafers 18 to the pod 9 or the boat 26 while the transfer machine 24 is decelerated.

To shorten a conveyance time of the wafers 18 and improve productivity, acceleration to the maximum speed is required in a short time from start of the operation. On the other hand, large torque acts on the transfer machine 24 by the acceleration, and there may be a case where a torque value generated at this time is larger than a torque value generated when the transfer machine 24 collides with another member.

A conveyance path of the wafers 18 in the X-axis direction includes: the interference area where the transfer machine 24, that is, a part of the wafers 18 or a part of the wafer mounting plate 25 may interfere with or contact another member such as the pod 9 or the boat 26; and the non-interference area where the transfer machine 24, that is, a part of the wafer 18 or a part of the wafer mounting plate 25 may not interfere with another member such as the pod 9 or the boat 26.

Accordingly, in the present practical example, different torque limit values are set for the non-interference area and the interference area, and the acceleration of the transfer machine 24 in the X-axis direction is performed only in the non-interference area, and the transfer machine 24 is moved at the constant speed or in a decelerated state in the interference area. In other words, a torque limit value is set for (advancing) operation toward the pod 9 or the boat 26 (advancing operation from the non-interference area to the interference area), and no torque limit value is set for (retracting) operation to be moved away from the pod 9 or the boat 26 (returning operation from the interference area to the non-interference area). This is to release the torque control in the interference area because there is no risk of collision at the time of the retraction in a case where no collision occurs in the advancing operation. In this case, in a case where the torque limit value is set for the time of retraction even when no wafer 18 is mounted, the torque is detected at the high-speed operation during the retraction from the pod 9 or the boat 26, thereby causing malfunction.

FIG. 5 provides graphs illustrating torque values acting on the transfer machine 24 at the time of advancing the transfer machine 24 toward the pod 9 or the boat 26 when the transfer machine 24 is moved from the pod 9 to the boat 26 or from the boat 26 to the pod 9. In FIG. 5, a vertical axis represents a detected torque value and a horizontal axis represents a conveyance distance of the wafers 18.

In FIG. 5, a reference sign 75 represents an acceleration torque value generated at the time of accelerating the transfer machine 24, a reference sign 76 represents a steady torque value at the time of moving the transfer machine 24 at the constant speed, and a reference sign 77 represents a collision torque value generated when the transfer machine 24 (wafer mounting plate 25 or wafers 18) collides with another member.

As illustrated in FIG. 5, the first torque limit value set for the non-interference area is set so as to be larger than the acceleration torque value 75. Additionally, the second torque limit value set for the interference area is set so as to be smaller than the acceleration torque value 75 and larger than the steady torque value 76. Note that the first torque limit value and the second torque limit value are set individually for the interference area and the non-interference area between the pod 9 and the wafer conveyance mechanism 24, and the interference area and the non-interference area between the transfer machine 24 and the boat 26. Furthermore, torque limit values can be set in accordance with the operation of the transfer machine as described above.

In the interference area, the steady torque value 76 becomes a maximum value in a normal state. In other words, an acceleration distance of the transfer machine 24 is set for the non-interference area such that the torque value acting on the transfer machine 24 is decreased from the acceleration torque value 75 to the steady torque value 76.

Note that the first torque limit value is appropriately set so as not to affect the conveyance of the wafers 18 in the non-interference area.

The closer to the steady torque value 76 the second torque limit value is, the more improved detection sensitivity of the collision torque value 77 is. On the other hand, in a case where the steady torque value is set close to the steady torque value 76, fluctuation of the torque value caused by vibration and the like is detected as the collision torque value 77, and there may be a possibility of causing malfunction.

Therefore, the second torque limit value is the steady torque value 76 or larger and also less than the acceleration torque value 75, and it is preferable that the second torque limit value be a value larger than, or close to, the maximum value of the steady torque value 76 that fluctuates due to various factors during constant-speed movement.

FIG. 6 illustrates a case where a wafer 18 on the substrate support 25 collides with the boat 26 in the interference area while the wafer 18 is being conveyed from the substrate support 25 of the transfer machine 24 to the boat 26. FIG. 7 illustrates an operation stop flow executed by the second-1 operation controller 56-1 that has detected abnormal torque caused by the collision in FIG. 6. Here, a description will be provided below while abbreviating the second-1 operation controller 56-1 simply as the second operation controller 56.

During the conveyance of the wafer 18, a torque value acting on the transfer machine 24, namely, the second operation actuator 61 is constantly detected by the torque sensor 81, and the detection result is fed back to the second operation controller 56.

The second operation controller 56 determines whether the torque value fed back from the torque sensor 81 is within the first torque limit value in the non-interference area and within the second torque limit value in the interference area.

As illustrated in FIG. 6, in a case where the wafer collides with the column of the boat 26, the torque value acting on the second operation actuator 61 is increased, and the collision torque value 77 exceeding the second torque limit value is detected by the torque sensor 81.

When the torque sensor 81 detects the torque value exceeding the second torque limit value, the second operation controller 56 stops accepting an operation signal from the main controller 41 via the conveyance controller 39 and deletes (resets) an operation signal that has been received in the second operation controller 56 as illustrated in FIG. 7. Furthermore, the second operation controller 56 notifies the main controller 41 of an abnormality of the torque value of the second operation actuator 61 as an alarm signal via the conveyance controller 39, and stops the drive of the second operation actuator 61.

Consequently, the operation of the transfer machine (second operation actuator 61) is stopped, and also thrust is lost (thrust free). Therefore, after the second operation actuator 61 is stopped, the boat 26 is not continually pressed by the transfer machine 24 (second operation actuator 61). Note that the thrust may be held while the drive of the second operation actuator 61 is stopped.

The main controller 41 displays, on the operational screen 73, the alarm signal provided as the notification. Additionally, the main controller 41 may issue, to the conveyance controller 39, a command to interrupt the conveyance processing of the wafer 18 based on this alarm signal although not illustrated in FIG. 7. Consequently, the conveyance controller 39 can interrupt the conveyance processing of the wafer 18 by stopping the normal operation actuators 62 and 63 having no abnormality caused in other second operation controllers 56. Furthermore, the conveyance controller 39 may interrupt, in accordance with the command to interrupt the conveyance processing, the conveyance processing of the wafer 18 by stopping the respective operation actuator 58, 59, 60, 62, 63, and 64 having no abnormality caused in the first operation controllers 55, the second operation controllers 56, and the third operation controller 57.

Thus, since the main controller 41 also issues, via the conveyance controller 39, the stop commands to the respective normal operation actuators having no abnormality caused in the second operation controllers 56, a collision component (boat 26) can be preferentially protected. Then, the conveyance processing of the wafer 18 is interrupted, and recovery processing (processing to solve the abnormality) is urged. For example, the main controller 41 displays, on an entire surface of the monitor 73, a message indicating that recovery processing is being performed.

As described above, in the present practical example, when the transfer machine 24 is moved to the pod 9 or the boat 26 in a conveyance step of the wafer 18 between the pod 9 and the boat 26, the torque control is executed by setting, for the interference area and the non-interference area, the first torque limit value and the second torque limit value different from each other.

Therefore, since the value of the second torque limit value to detect a collision between the wafer 18 or the like and another member is set for the interference area regardless of the acceleration torque value 75 at the time of accelerating the transfer machine 24, the collision torque value 77 increased by the collision is quickly detected, the operation of the transfer machine 24 can be stopped, and damage to the members such as the wafer 18 and the boat 26 at the time of the collision can be suppressed.

Furthermore, when the torque sensor 81 detects the collision torque value 77 exceeding the second torque limit value, the second operation controller 56 immediately stops the drive of the second operation actuator 61 and simultaneously notifies the main controller 41 of the abnormality of the torque value of the second operation actuator 61 by using an alarm signal.

According to the present embodiments, a countermeasure in the event of collision can be collectively performed in the second operation controllers (by stopping the second operation actuator 61 upon detection of the collision) without using an external signal. Therefore, when a second operation controller 56 is normally operated, the operation stop can be surely performed and a time lag from the collision to the stop can be minimized. Consequently, communication can be performed between the second operation controllers 56, the conveyance controller 39, and the main controller 41, and the drive of the second operation actuator 61 in which an abnormality that has occurred can be stopped without exchanging any signal, and therefore, the time lag from detection of the collision torque value 77 to the stop of drive of the second operation actuator 61 can be reduced, and damage to collision members can be suppressed.

Furthermore, according to the present embodiments, when the collision torque value 77 is detected and the second operation controller 56 stops the drive of the second operation actuator 61, thrust of the wafer conveyance mechanism 24 is also automatically lost. Therefore, the damage to the collision members can be suppressed because the thrust is not continually applied to the member with which the wafer 18 or the like collided.

Furthermore, according to the present embodiments, in the conveyance step of the wafer 18 between the pod 9 and the boat 26, the second operation controller 56 does not perform the torque control in the operation in which the transfer machine 24 is moved away from the pod 9 or the boat 26. The reason is that there is no risk of collision because contact between the substrate support 25 and the wafer 18 is completed. Rather, the second operation controller 56 operates the transfer machine 24 with maximum acceleration at the maximum speed. Consequently, a conveyance operation time can be shortened, and therefore, throughput is effectively improved.

Note that, in the present embodiments, the different torque limit values are set for the interference area and the non-interference area respectively relative to the conveyance processing in the X-axis direction of the wafer conveyance mechanism 24 by the second operation actuator 61, and two-stage torque control is executed, but the torque control is not limited to the above-described conveyance processing, and multiple-stage torque control may also be executed.

For example, two-stage torque control may be executed for the first operation actuator 58 controlled by the first operation controller 55-1. For example, the two-stage torque control described above may also be executed for the second operation actuator 62 that horizontally rotates the wafer conveyance mechanism 24 in the Y-axis direction. Furthermore, needless to mention, the above-described two-stage torque control may be executed in any conveyance step having a risk that a wafer 18 collides with another member during the conveyance.

Note that the operational unit 74 according to the practical example of this present disclosure can be implemented by using a general computer system without using a dedicated system. For example, the operational unit that executes the above-described processing can be implemented by installing, in a general-purpose computer, programs to execute the above-described processing from a recording medium (USB memory or the like) that stores the programs.

Additionally, a means to supply the programs (for example, installer) is arbitrary. The programs can be supplied not only via the predetermined recording medium as described above but also may be supplied via, for example, a communication line, a communication network, a communication system, and the like. In this case, for example, the programs may be posted on a bulletin board of the communication network and provided in a manner superimposed on a carrier wave via the network. Additionally, the above-described processing can be executed by activating the programs thus provided and executing the programs under the control of an OS in a manner similar to other application program.

Note that the substrate processing apparatus 1 according to the present embodiments is applicable not only to a semiconductor manufacturing device but also to a device like an LCD device that processes a glass substrate, and does not depend on a process. For example, the substrate processing apparatus 1 is applicable to, for example, CVD, PVD, processing to form an oxide film or a nitride film, processing to form a film containing a metal, annealing, oxidation, diffusion processing, and the like.

Needless to mention that the substrate processing apparatus 1 is applicable not only to the semiconductor manufacturing device but also to other substrate processing apparatuses such as an exposure apparatus, a lithography apparatus, a coating apparatus, a CVD apparatus using plasma, and the like.

This present disclosure is applicable to an actuator that executes an operation command within a limit value of rated torque and within a scope of an operation command. Additionally, this present disclosure is also applicable to a unit and a device which include this actuator.

According to this present disclosure, damage to the substrate and the substrate holder can be suppressed by monitoring the transfer machine during substrate conveyance and urgently stopping the transfer machine in the event of an abnormality. 

The invention claimed is:
 1. A substrate transfer unit comprising: a transfer machine configured to charge a substrate contained in a substrate container to a substrate holder; a drive member configured to operate the transfer machine; and an operation controller configured to monitor whether a torque value detected from the drive member is kept within a torque limit value of the transfer machine by comparing the torque value with the torque limit value, the torque limit value being individually set for each of an interference area and a non-interference area excluding the interference area relative to conveyance operation in which the transfer machine is moved toward at least one of the substrate container and the substrate holder, the torque limit value in the non-interference area being set larger than the torque limit value in the interference area where a part of the transfer machine interferes with at least one of the substrate container and the substrate holder.
 2. The substrate transfer unit according to claim 1, wherein in a case where the torque value detected from the drive member during transfer of the substrate exceeds the torque limit value, the operation controller is configured to make the drive member stop the transfer machine.
 3. The substrate transfer unit according to claim 1, wherein the drive member is configured to accelerate the transfer machine when operation is started, the drive member is configured to move the transfer machine at a constant speed during the operation, and the drive member is configured to decelerate the transfer machine when the operation is finished, and a torque limit value at the time of the acceleration is set larger than torque limit values at the time of a constant speed and at the time of the deceleration.
 4. The substrate transfer unit according to claim 2, wherein the operation controller is configured to be capable of selecting and setting, for the drive member, whether the transfer machine keeps thrust at a stop position or becomes free from the thrust after the transfer machine is stopped.
 5. The substrate transfer unit according to claim 1, wherein the transfer machine further includes a substrate support configured to hold the substrate, and the operation controller monitors whether the torque value detected from the drive member is within the torque limit value that is set individually for each of: the interference area where the substrate support interferes with at least one of the substrate container and the substrate holder; and the non-interference area where the substrate support does not interfere.
 6. The substrate transfer unit according to claim 1, wherein the operation controller is configured so as not to compare the torque value with the torque limit value relative to conveyance operation in which the transfer machine is moved away from at least one of the substrate container and the substrate holder.
 7. A substrate processing apparatus comprising: a transfer machine configured to charge a substrate contained in a substrate container to a substrate holder; a drive member configured to operate the transfer machine; an operation controller configured to monitor whether a torque value detected from the drive member is kept within a torque limit value of the transfer machine by comparing the torque value with the torque limit value, the torque limit value being individually set for each of an interference area and a non-interference area excluding the interference area relative to conveyance operation in which the transfer machine is moved toward at least one of the substrate container and the substrate holder, the torque limit value in the non-interference area being set larger than the torque limit value in the interference area where a part of the transfer machine interferes with at least one of the substrate container and the substrate holder; and a conveyance controller configured to command the operation controller to convey the substrate.
 8. The substrate processing apparatus according to claim 7, wherein in a case where the torque value detected from the drive member during transfer of the substrate exceeds the torque limit value, the operation controller is configured to make the drive member stop the transfer machine.
 9. The substrate processing apparatus according to claim 8, wherein the operation controller is configured to be capable of selecting and setting, for the drive member, whether the transfer machine keeps thrust at a stop position or becomes free from the thrust after the transfer machine is stopped.
 10. The substrate processing apparatus according to claim 7, wherein the drive member is configured to accelerate the transfer machine when operation is started, the drive member is configured to move the transfer machine at a constant speed during the operation, and the drive member is configured to decelerate the transfer machine when the operation is finished, and a torque limit value at the time of the acceleration is set larger than torque limit values at the time of a constant speed and at the time of the deceleration.
 11. The substrate processing apparatus according to claim 7, wherein the torque limit value is not set relative to operation in which the transfer machine is moved away from at least one of the substrate container and the substrate holder.
 12. The substrate processing apparatus according to claim 7, wherein the transfer machine further includes a substrate support configured to hold the substrate, and the operation controller monitors whether the torque value detected from the drive member is within the torque limit value that is set individually for each of: the interference area where either a part of the substrate support or the substrate interferes with at least one of the substrate container and the substrate holder; and a non-interference area where either a part of the substrate support or the substrate does not interfere.
 13. The substrate processing apparatus according to claim 7, further comprising an operational unit including a setting screen to set at least the torque limit value, wherein the conveyance controller is configured to control the operation controller so as to operate the transfer machine in accordance with at least one or more items set on the setting screen from among items including a torque limit value set for the transfer machine, a setting for the drive member after transfer of the substrate.
 14. The substrate processing apparatus according to claim 13, wherein the conveyance controller is configured to control the operation controller so as to operate the transfer machine in accordance with content respectively set on the setting screen for: conveyance operation in which the transfer machine is moved toward at least one of the substrate container and the substrate holder; and conveyance operation in which the transfer machine is moved away from at least one of the substrate container and the substrate holder. 